1. Field of the Invention
The present invention relates generally to vinyl ester urethane resins, to methods of preparing said resins, and to compositions containing said resins. More particularly, the invention relates to vinyl ester urethane resins having the following general formula: EQU B--I--A--M.sub.y A--I--B
wherein
A is a radical derived from a polyoxyalkylene bisphenol A having the the following formula: ##STR1## wherein R' is C.sub.1 -C.sub.4 alkylene group,
X is halogen PA2 a is an integer equal to from 0 to 2, and PA2 m and n are integers each of which is equal to at least 1 and the sum of which is equal to from about 9 to about 30; PA2 X is halogen PA2 a is an integer equal to from 0 to 2, and PA2 m and n are integers each of which is equal to at least 1 and the sum of which is equal to from about 9 to about 30;
M is a radical derived from (A) an unsaturated, aliphatic, polycarboxylic acid or an anhydride thereof, (B) a saturated aliphatic polycarboxylic acid or an anhydride thereof, (C) an aromatic polycarboxylic acid or anhydride thereof or (D) mixtures of A, B, or C;
I is a radical derived from a polyfunctional isocyanate;
B is a radical derived from a monohydroxyl-terminated ester of acrylic acid;
y is an integer equal to from 1 to about 12; .
The resins are prepared by reacting a polyfunctional isocyanate and a monohydroxyl-terminated ester of acrylic acid with the condensation product prepared by reacting a polyoxyalkylene bisphenol A with a polycarboxylic acid or anhydride. The resins are useful in coating compositions and particularly useful in coatings which are curable by radiation.
2. Description of the Prior Art
Vinyl ester urethanes are known in the art. See for example Ford, E. C. Jr., et al., U.S. Pat. No. 3,876,726 which discloses vinyl ester urethanes prepared by reacting a polyoxyalkylene bisphenol A with an unsaturated aliphatic dicarboxylic acid and reacting the product thereof with a diisocyanate and a hydroxyl-terminated ester of a methacrylic or an acrylic acid. It has now been discovered that certain vinyl ester urethanes having a specific number of oxyalkylene units and other specific limitations possess a combination of excellent properties in the areas of desirable uncured resin viscosity, and which yield cured coatings possessing such properties in areas as solvent resistance, corrosion resistance in various acidic or alkaline environments, pencil hardness, abrasion resistance, high gloss potential, high pigment loading, adhesion, impact (both direct and reverse) strength, and metal adherence.